RESUMEN
Gamma irradiation as a decontaminating physical agent could be an important tool in the production chain of herbal medicines by improving the microbiological quality of raw materials and the safety of final products. This study was undertaken to investigate the genotoxic potential and eventual chemical modifications of a batch of Mikania glomerata raw material decontaminated by different doses of gamma irradiation (2.0, 3.5, and 5.0 kGy), using a cesium-137 source. DNA damage was assessed in vitro by agarose gel electrophoresis in regard to double-chain breaks of plasmid pUC 9.1 DNA and in vivo by micronucleus test in bone marrow cells of Wistar rats. Cytotoxicity in bone marrows was assessed by scoring polychromatic and normochromatic erythrocytes ratio. An HPLC-DAD method was adapted and validated for the enhancement of coumarin selectivity from the other matrix constituents. The microbial load was satisfactorily reduced, leading to sterilization at the highest dose. Genotoxic and cytotoxic effects were not increased in the in vitro and in vivo models. The concentration of coumarin and the chromatographic profiles of the hydroalcoholic plant extracts (ethanol 70% v/v) were not modified after such process. Therefore, this work suggests that gamma irradiation of M. glomerata raw material is suitable and safe for microbiological control purposes at the employed doses.
Asunto(s)
Daño del ADN/efectos de los fármacos , Descontaminación/métodos , Mikania/química , Extractos Vegetales/efectos de la radiación , Hojas de la Planta/efectos de la radiación , Animales , Médula Ósea/efectos de los fármacos , Cromatografía Líquida de Alta Presión/métodos , Cumarinas , Electroforesis en Gel de Agar , Rayos gamma , Masculino , Pruebas de Micronúcleos , Mikania/microbiología , Extractos Vegetales/toxicidad , Hojas de la Planta/química , Hojas de la Planta/microbiología , Ratas WistarRESUMEN
Although food irradiation has been used to ensure food safety, most consumers are unaware of the basic concepts of irradiation, misinterpreting information and demonstrating a negative attitude toward food items treated with ionizing radiation. This research is aimed at developing a tool to assess the awareness on the consumption of irradiated food. The sample was composed by employees from different social classes and school levels of Brazilian universities, who reflect the end-users of the irradiated foods, representative of the views of lay consumers. The total number of respondents was 614. In order to assess the Awareness Scale on Consumption of Irradiated Foods (ASCIF), an instrument has been developed and submitted to semantic tests and judge's validation. The instrument, that included 32 items, contemplated four construct factors: concepts (6 items), awareness (10 items), labeling (7 items) and safety of Irradiated foods (9 items). The data were collected by electronic means, through the site
Asunto(s)
Concienciación , Irradiación de Alimentos , Psicometría , Adulto , Brasil , Análisis Factorial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
This study aimed at evaluating the bacteriological effects of the treatment of sheep meat contaminated with total coliforms, coliforms at 45 °C and Salmonella spp. by using irradiation at doses of 3 kGy and 5 kGy. Thirty sheep meat samples were collected from animals located in Rio de Janeiro State, Brazil, and then grouped in three lots including 10 samples: non-irradiated (control); irradiated with 3 kGy; and irradiated with 5 kGy. Exposure to gamma radiation in a 137Cs source-driven irradiating facility was perfomed at the Nuclear Defense Section of the Brazilian Army Technological Center (CTEx) in Rio de Janeiro. The samples were kept under freezing temperature (-18 °C) until the analyses, which occurred in two and four months after irradiation. The results were interpreted by comparison with the standards of the current legislation and demonstrated that non-irradiated samples were outside the parameters established by law for all groups of bacteria studied. Gamma irradiation was effective in inactivating those microorganisms at both doses tested and the optimal dose was achieved at 3 kGy. The results have shown not only the need for sanitary conditions improvements in slaughter and processing of sheep meat but also the irradiation effectiveness to eliminate coliform bacteria and Salmonella spp.
Asunto(s)
Animales , Desinfección/métodos , Enterobacteriaceae/aislamiento & purificación , Enterobacteriaceae/efectos de la radiación , Rayos gamma , Carne/microbiología , Salmonella/aislamiento & purificación , Salmonella/efectos de la radiación , Brasil , Microbiología de Alimentos/métodos , Ovinos , TemperaturaRESUMEN
In the present study the effects on shelf life and sensory acceptance of gamma-irradiated refrigerated poultry breast fillets subjected to modified atmosphere packaging (80% CO2/20% N2 or vacuum) were investigated. After irradiation with 2 kGy, sensory acceptance tests and monitoring of bacterial growth were performed in order to determine the sanitary quality of the samples. It has been found that irradiation, used in combination with modified atmosphere packaging, can double the shelf life of refrigerated poultry breast fillets by reducing the populations of aerobic mesophilic and psychrotrophic bacteria, enterobacteria, coliforms, Listeria spp. and Aeromonas spp., without significantly modifying its color or its overall appearance, the lactic acid bacteria being the most resistant to exposure to radiation and carbon dioxide.
Asunto(s)
Animales , Bacterias Aerobias/aislamiento & purificación , Bacterias Aerobias/patogenicidad , Bacterias Anaerobias/aislamiento & purificación , Bacterias Anaerobias/patogenicidad , Conservación de Alimentos/métodos , Crecimiento Bacteriano/métodos , Dióxido de Carbono/análisis , Irradiación de Alimentos , Productos Avícolas , Microbiología de Alimentos , Gestión de la Calidad Total , Métodos , Aves de CorralRESUMEN
O objetivo do presente estudo foi avaliar os efeitos dos processos de irradiação (com dose de 1,5kGy) e embalagem em atmosfera modificada (60% N2 e 40% CO2), aplicados isoladamente ou combinados, na extensão da validade comercial de filés de Tilápia do Nilo (Oreochromis niloticus) resfriados. Nos experimentos, foram utilizados 120 filés separados em lotes, de acordo com o tratamento: (T1) embalagem em ar (controle), (T2) embalagem em atmosfera modificada, (T3) embalagem em ar e irradiação, (T4) embalagem em atmosfera modificada e irradiação. Foram realizadas análises físico-químicas (BVT, TMA, pH, amônia e TBARS), bacteriológicas (contagem de bactérias heterotróficas, aeróbias, mesófilas e psicrotróficas) e avaliação sensorial. Os resultados consistentemente indicaram uma redução progressiva da qualidade do produto com o tempo de armazenamento, a qual foi significativamente mais rápida nas amostras controle do que naquelas submetidas aos demais tratamentos, tendo sido observada uma extensão na validade comercial dos filés embalados em atmosfera modificada e/ou irradiados de 4 dias para aproximadamente duas semanas.
This paper investigated the effects of modified atmosphere packing (60% N2 and 40% CO2) and irradiation (with a 1.5kGy dose) either used alone or combined on the shelf life of fillets of refrigerated Nile Tilapia. A total of 120 fillets were used in the experiments in order to test four different treatments and included samples: packed in air (control), packed in modified atmosphere, packed in air and irradiated, and finally, packed in modified atmosphere and irradiated. Regular monitoring of physicochemical parameters (TVB, pH, ammonia and TBARS), bacteriological conditions (heterotrophic aerobic mesophilic and psychrotrophic bacteria) and sensory acceptance were performed. The results consistently indicated an increasing deterioration of the fillets with time, however those treated with irradiation, modified atmosphere or both combined had longer shelf lives (around two weeks) in comparison with the control (4 days only).
RESUMEN
No presente trabalho foram analisadas amostras de músculo e gônadas de vieira crus e congelados, oriunda de maricultura de Angra dos Reis, Rio de Janeiro, Brasil. Esta pesquisa teve como finalidade a verificação da eficiência da irradiação, utilizando-se doses de 2kGy e 5kGy. Na Contagem de Bactérias Heterotróficas Aeróbias Mesófilas (CBHAM) observou-se diferença estatisticamente significativa do grupo controle em relação ao grupo irradiado a 5kGy; enquanto que para a Contagem de Bactérias Heterotróficas Aeróbias Psicrotróficas (CBHAP) não se observou nenhuma diferença estatisticamente significativa entre os grupos avaliados. O Número Mais Provável (NMP) de Enterococcus spp. não teve sua presença evidenciada em nenhuma das amostras analisadas. Conclui-se que a irradiação, nesta pesquisa, foi eficiente somente para bactérias mesófilas na dose de 5kGy.
The present article investigated the effectiveness of irradiation process to conservate frozen raw scallops muscle and gonads. Samples of this animal were collected from cultivated areas at Angra dos Reis, Rio de Janeiro state, Brazil. The samples were submitted to treatment of 2 and 5 kGy doses. Mesophilic Aerobic Heterotrophic Bacteria Count showed a statistically significant difference from the control group related to the 5kGy one, while for the Heterotrophic Bacteria Aerobic Psychrotrophic Count were not observed any statistically significant difference among the analysed groups. The Most Probable Number of Enterococcus spp. was not evident in any of the samples. It was concluded that irradiation was effective only for mesophilic bacteria using the 5kGy dose in this research.
Asunto(s)
Animales , Bacteriología/tendencias , Músculos/anatomía & histología , Pectinidae/clasificación , Moluscos/clasificaciónRESUMEN
This work investigated the effects of different packaging methods (air and vacuum) combined with irradiation (0.0, 2.0 and 3.0 kGy) on the preservation of chicken breast fillets stored at 1ºC for up to 18 days by sensorial test, determination of pH and bacterial growth. The findings indicated that the post-irradiation lag phase increased with the dose, leading to an extension in shelf-life. Vacuum-packed samples irradiated at 3.0 kGy exhibited the longest shelf life. Among the analyzed bacteria, coliforms and Listeria spp. were most sensitive to gamma radiation. All the fillets acquired more attractive coloration and better overall impression with irradiation. The combined use of vacuum packaging and irradiation (3.0 kGy) reduced the microbial populations without causing change in pH and yielded a significant shelf-life extension of refrigerated fillets, besides improving its appearance.
RESUMEN
A irradiação de alimentos é uma opção tecnológica para minimizar problemas de perdas de alimentos, pois reduz asalterações provenientes da atividade bacteriana, estendendo a validade do produto. Neste estudo foram irradiados camarões(Litopenaeus brasiliensis) com doses de 1,5 e 2,5 kGy, após 30 dias de armazenamento sob refrigeração (2°C ± 2°C), como objetivo de avaliar os efeitos da irradiação sobre a validade comercial de camarões através de parâmetros físico-químicos,microbiológicos e sensoriais. Foram avaliados pH, bases voláteis totais (BVT), contagem de bactérias heterotróficas aeróbiasmesófilas (BHAM) e heterotróficas aeróbias psicrófilas (BHAP) e teste de aceitação sensorial. Os valores de pH não variaramentre as amostras controle e as amostras irradiadas apresentando média de 7,08 ± 0,21 durante os 30 dias de armazenamento.A produção de BVT nas amostras controle extrapolou o limite aceitável para o consumo no 15o dia de armazenamentoenquanto nas amostras irradiadas com 2,5 kGy, este limite não foi alcançado em 28 dias de armazenamento, demonstrandoo efeito positivo da utilização da irradiação. Na análise sensorial, não ocorreu diferença significativa (p> 0,01) na aceitação,quanto aos atributos de sabor, aparência, aroma e impressão global entre as amostras.
Food irradiation is currently regarded as a technological option to mitigate food losses due to its potential in reducing microbiological load and its associated spoilage effects, consequently extending the shelf life of many products. Samples of shrimp (Litopenaeus brasiliensis) have been exposed to gamma doses of 0, 1.5 and 2.5 kGy and monitored changes in sensorial characteristics (30 judges), pH and total volatile bases (TVB) levels. All samples were kept at 2°C ± 2°C through the experiments. No significant change in pH has been observed during the experiments regardless of the gamma dose applied. There was statistical difference between the non-irradiated samples and those irradiated with 2.5 kGy (p 0.01), though no significant difference has been found between the non-irradiated samples and those irradiated with 1.5 kGy nor between the samples irradiated with 1.5 kGy and those irradiated with 2.5 kGy. Based on the upper commercial limit for NB, non-irradiated samples achieved the limit in 15 days while the samples irradiated with 2.5 kGy didnt achieve the limit in 28 days. In sensorial analyses, there was no significant difference (p> 0.01) in the acceptance, according to the attributes flavor, appearance, aroma and global impression among the samples.
Asunto(s)
Animales , Penaeidae/microbiología , Penaeidae/química , Refrigeración , Refrigeración/clasificación , Refrigeración/veterinariaRESUMEN
O objetivo deste experimento foi investigar o efeito da radiação gama sobre a micobiota natural de ingredientes e ração avícola e seu impacto sobre espécies de Aspergillus spp. Para tanto, fubá, farelo de soja e ração foram expostos a uma fonte de césio-137 nas doses 0; 3,5; 8 e 15kGy. Amostras de milho, inoculadas com suspensão de conídios de Aspergillus spp., foram irradiadas com doses de 0 a 8kGy. Observou-se redução das contagens com o aumento da dose, obtendo-se eliminação da micobiota com 8kGy. Uma maior radiossensibilidade de leveduras foi observada em comparação a fungos filamentosos, e aqueles que resistiram à dose de 3,5kGy pertenciam, em sua maioria, aos gêneros Cladosporium spp., Curvularia spp., Fusarium spp. e Aspergillus spp. As espécies A. flavus e A. parasiticus mostraram-se mais radiorresistentes que as demais avaliadas. Redução na conidiogênese e presença de estruturas de resistência foram detectadas logo após a irradiação. Constatou-se também que, após repiques em meios nutritivos, os isolados irradiados recuperaram a taxa de crescimento normal. Verificou-se ainda que o estresse metabólico induzido pela irradiação promoveu aumento na produção de aflatoxina B1 e ocratoxina A.
This experiment investigated the effects of gamma radiation on the mycoflora of natural ingredients and poultry feed, and its impact on species of Aspergillus spp. Corn meal, soybean meal, feed and maize (inoculated with spore suspension of Aspergillus spp.) were irradiated with 0, 3.5, 8 and 15kGy by exposure to a 137Cs source. Increasing radiation doses led to lower counts so elimination of mycoflora was observed at 8kGy. In addition, filamentous fungi exhibited a greater resistance to radiation than yeasts and those that withstood 3.5kGy were mostly Cladosporium spp., Curvularia spp., Fusarium spp. or Aspergillus spp. A. flavus and A. parasiticus have been found to be the most resistant among the species studied. Post-irradiation reduction in the spore production as well as presence of resistance structures have been observed. When such altered colonies were isolated and grown on nutritional media again, they recovered their normal growth pattern. In addition, a significant increase in the production of aflatoxin B1 and ochratoxin A was found, probably due to metabolic stress caused by irradiation.
RESUMEN
Amostras de mel puro de floradas silvestres, de mesma origem, foram irradiadas em Irradiador Gamma Cell, 220, Nordion, no LIN/COPPE/URFJ, com fonte gama de 60°C. O mel foi distribuído em potes de polietileno, de 400 g e irradiado com as doses de 5KGy, 10 KGy, 15 KGy e 25 KGy, à temperatura de 20°C, RJ.C. Potes de mel não-irradiados foram separados para controle. As amostras foram submetidas às análises físico-químicas de: acidez livre, açúcares redutores, coloração, índice de HMF, insolúveis, Ph, sacarose aparente, umidade, odor e atividade diastásica, recomendadas pela SND/Ministério da Agricultura (LA-NARA), conforme as normas do CAC e AOAC. Os resultados mostraram que mesmo para a dose mais elevada (25 KGy), as alterações foram muito pequenas. Apenas a coloração foi mais alterada, mudando para um âmbar ligeiramente mais claro. Na análise sensorial usou-se a escala hedônica de 7 pontos, com participação de 30 consumidores escolhidos aleatoriamente. A análise estatística dos resultados foi feita pela Análise de Variança (ANOVA) e o Teste de Tukey ao nível de 1 por cento, para as preferências entre os atributos dos grupos. As diferentes doses de radiação não produziram diferenças significativas no aroma e no sabor, mas apenas na cor. Comparando com a amostra não-irradiada, as irradiadas diferiram 0,05 por cento na cor, 0,2 por cento no sabor e 0,02 por cento no aroma.
Asunto(s)
Análisis de los Alimentos , Irradiación de Alimentos , MielRESUMEN
A presente pesquisa, investigou a eficácia da aplicação da radiação gama para evitar o aparecimento de fungos patogênicos em amendoim (Arachis hypogea, L), conseqüentemente, conferindo ao produto uma melhor qualidade fitossanitária e maior vida de prateleira. Foram pesquisadas amostras processadas salgadas e in-natura. Depois de submetidas à radiação proveniente de uma fonte de césio-137, para absorverem doses de 0; 1,5; 2,0 e/ou 2,5 kGy, as amostras foram monitoradas sensorial e micologicamente e comparadas às testemunhas (não irradiadas). Análises sensoriais periódicas mostraram que o tratamento por irradiação com dose de 2,0 kGy não alterou perceptivelmente o sabor do amendoim in-natura, mas causou uma evidente alteração no sabor das amostras de amendoim processado.(...).